1 files changed, 13 insertions, 2 deletions
diff --git a/contrib/llvm/lib/CodeGen/RegisterClassInfo.h b/contrib/llvm/lib/CodeGen/RegisterClassInfo.h
index d21fd67..2c14070 100644
--- a/contrib/llvm/lib/CodeGen/RegisterClassInfo.h
+++ b/contrib/llvm/lib/CodeGen/RegisterClassInfo.h
@@ -28,11 +28,12 @@ class RegisterClassInfo {
   struct RCInfo {
     unsigned Tag;
     unsigned NumRegs;
+    bool ProperSubClass;
     OwningArrayPtr<unsigned> Order;
 
-    RCInfo() : Tag(0), NumRegs(0) {}
+    RCInfo() : Tag(0), NumRegs(0), ProperSubClass(false) {}
     operator ArrayRef<unsigned>() const {
-      return ArrayRef<unsigned>(Order.get(), NumRegs);
+      return makeArrayRef(Order.get(), NumRegs);
     }
   };
 
@@ -87,6 +88,16 @@ public:
     return get(RC);
   }
 
+  /// isProperSubClass - Returns true if RC has a legal super-class with more
+  /// allocatable registers.
+  ///
+  /// Register classes like GR32_NOSP are not proper sub-classes because %esp
+  /// is not allocatable.  Similarly, tGPR is not a proper sub-class in Thumb
+  /// mode because the GPR super-class is not legal.
+  bool isProperSubClass(const TargetRegisterClass *RC) const {
+    return get(RC).ProperSubClass;
+  }
+
   /// getLastCalleeSavedAlias - Returns the last callee saved register that
   /// overlaps PhysReg, or 0 if Reg doesn't overlap a CSR.
   unsigned getLastCalleeSavedAlias(unsigned PhysReg) const {